There has been a rumor or two floating about that 7th edition may be coming quite soon on the heels of some of the releases later this year. For those of us who bought into the collector's edition of 6th edition, it's a little disconcerting to think it'll be outdated in less than two years time. My personal thoughts on what this "7th edition" rumoring revolves around less of a new edition, and more of a culmination of all the new information we've seen drop over the blitzkrieg of units, rules, codexes, dataslates, supplements, expansions and more. Basically think of a re-release of the current rules, but with all of the new information added into it. That is at least my hopes on it with regards to an edition shift.
However, there is a chance for Games Workshop to make some balance changes to some of the game's mechanics as it moves forward. Whether or not they choose to with this new edition we hear talk of is another story, but they could make some nice tweaks in the form of potent erratas. A few rules came up in my mind of places where the game could make changes that really improve the ability and increase tactical options presented to the players. You can disagree with the power level of a specific unit or codex all you want, but at the end of the day it pays to remember that all of these issues are made possible by existing in the context of the game's rules. So let's look at some of these possible alterations to some of the game's existing rules to see how we could change the scheme or alter the mood of 40k.
Applying the Split Fire USR on a Broader Scale

This rule would need to have some balance applied to it to keep it in check. Allowing a unit to just fire at two separate targets just because could not only allow some units to be a little too potent, but it would also slow the game dramatically. To me, this rule should be allowed for models with unique wargear as compared to the squad they are with. Perhaps only allowing wargear that was purchased above or by replacing the model's standard issue wargear, and is unique within a squad. The first part insures that you can't just split fire bolters, while the latter helps balance it in the case of units which can purchase a high number of special or heavy weapons (such as CSM Chosen or Dark Eldar Trueborn).
This thought could be flushed out more, but the idea feels solid to me. It's something that most every army, Xenos and Marines alike could take advantage of, and allows the game itself to more accurately depict units in a warzone.
Re-balancing the Overwatch USR
Ok, so along with 6th edition came about this brand spankin' new rule. There's not much need to go into what it does, since pretty much everyone knows it by now. Not only did the rule come out, but we've seen it become a lot more than what it looks like initially with certain units or characters getting to fire at normal BS when overwatching, and of course the Tau Markerlight increase thanks to Supporting Fire. Whatever the case, even if not bolstered, it still applies a new rule that basically takes place only in the "Declaring Assaults" phase of the game. However, there is another rule that has existed for many a year that also only takes place during this particular moment of the phase.
Units which charge into cover, that do not have some form of assault grenade have their Initiative cut to one for that turn, as the enemy "has fortified their position in cover." This means that currently a unit which does not have grenades can be hit with overwatch, and still be reduced to initiative 1. To me this seems a bit off. A unit that is taking the time to make a last ditch effort to volley into the charging enemy should not really be considered "bunkered down and ready for the assault." It somewhat shows when they are firing so at such a poor ballistic skill.
To me, I feel that since these rules overlap, there should be a choice made, rather than just static benefits. A unit should have the choice to be allowed to overwatch, resolved exactly as it is now, or gain the benefit of reducing the enemy unit to Initiative 1. This presents a tactical decision for players (on both sides of the assault), and also makes cover a little less of a mainstay defensive option for every unit. While most units in the game do indeed have frag grenades thus making most players still opting for the overwatch option, in the case that the assaulting unit doesn't it may help to make those units feel a little less pressured by the potency of Overwatch compounded with the Initiative reduction. This mainly effects Xenos, but the bigger thing here is that it helps Close Combat units in an edition that really favors the shootier units out there. This tweak to Overwatch could at least allow for more options for players, and make cover a little more dynamic in it's uses on the table.
Reworking & Creating More Defensive Options
The rule or ability "Going to Ground" makes a lot of sense in many ways. A unit that is about to be bombarded by enemy fire my drop to the deck and really dig in to their cover for the best possible chance of surviving, and forgoing all offensive capabilities to do so. However, both in reality and on the table, this can really be problematic as it slows the unit's ability to act in the coming moments.
Basically if a unit chooses to go to ground (or is forced to via Pinning) then they will recieve benefits to their cover saves, but can not move and snap fires until then end of the owning player's next turn. This means that the unit can not operate on the following turn, and is pretty much out of play. Well why not allow for something a little less damaging, but yielding a little less potency.
If we increased the save for going to ground to a default +2 cover save (as units currently receive if going to ground in Area Terrain or behind a Wall) in all situations, and still maintained the penalties currently inflicted upon them, then that leaves us room for a new option.
For now, I'll just call it Digging In. Drawing a little from the idea of the old Death Korps rules, the unit must forgo moving, shooting, and assaulting in a single turn, but will benefit from a +1 bonus to their cover saves (this does not generate a 6+ if they do not currently have a cover save [you can't dig in if there's nothing to dig in to]). However, the unit can function normally on the owning player's following turn.
This option allows players to move units into position, and having them dig in, and wait to strike. It doesn't provide as much bonus as going to ground, but does offer more chances for the unit to act quicker. This is a classic example of creating a choice, thus presenting more options for players to consider for their tactics. Currently defenses are summed up by "are you in cover?" and "Did you go to ground?" I feel that since there have been a plethora of new options presented for offense (particularly in ranged combat such as Focus Fire), it's only natural that I'd like to see more options for defending myself against those tactics.
So I guess there you have it. These are some ideas I'd had on perhaps rethinking some of the rules we have, and maybe tweaking some to allow for all news ones to become possible. I really think the above make a lot of sense for providing players with more options, which make sense tactically and out of common sense. Anything the design team does that makes the game less about what codex you run, the powerhouse units, alpha-strikes, or rules abuse and more about turns 2-7, tactical decisions, and maybe adhering a smidgen closer to their own fluff is a positive step in my eyes.
Personally I hope the rules don't shift too much. Games Workshop has a bad habit of over-correcting their systems. I'd say that some things in ranged combat could be a little toned back, but I can't help as a player but feel those issues have stimed more from codex designs rather than core rules discrepencies. That said, a lot of attention seemed to be payed to the shooting phase with 6th, and not quite as much to the defenses or the answers for those improvements. Perhaps if they do come out with a Warhammer 40k 6.5, these changes could help improves the game as well as the surplus of content like Escalation and Strongpoint Assault which would obviously be wrapped in. At any rate, here's to hoping the game continues to improve.
Cheers!